Matte objects reflections

[giandosopaolo]

Hi 

Question 1:

I was experimenting with the arnold Matte option which you can select per object (in the arnold section of each shape node to be precise). 

I noticed that when I use that, differently from the Matte option of the arnold standard shaders (which you can select per shader), the  reflections, and indirect light contributions of the matted objects are not calculated in the scene at all. 

Is it by default?

Question 2:

Is there a way to add a matte assignment to the Shader (not per object) of an .ass file standin?

I can only see the option appear as an assignment on the geometry in the arnold standin, but not on the shader (which prevents from having its reflections appear in the scene). All the other material prorperties can be selected as 

assignments, but not mette..

[Stephen.Blair]

1. The matte parameter on an object affects primary rays (aka camera rays) only.
The two matte spheres on the left are still visible to transmission and specular and indirect diffuse rays.

[Stephen.Blair]

2. You mean using operators? You'd have to select the standard_surface shaders in the ass file, and set the standard_surface.matte parameter

[giandosopaolo]

Hi @Stephen.Blair 

So, If I click the Enable Matte on the shader I obtain exactly the desired result. 

When I use the MATTE on the shader

However, If I do it on the shape node (what i would like to do) this happens. How come it renders different?

When I use the MATTE on the shape.

Regarding the standins, here I imported an.ass file (the green cube)

Here I imported an .ass file (the green cube)

If I click on the "matte" assignment on the object in the hierarchy, I obtain the same behavior of clicking on the "matte" option on the shape node.

If I use the matte assignment Iget the same behaviour of using the MATTE option on the shape node.

Instead I can not find anything on the shader that says standard_surface.matte. Am I looking in the wrong place?

[giandosopaolo]

Any idea of why is this happening, is this a bug?